Genetic Study On CYP1B1 Gene And Other Candidate Loci Of Infantile Glaucoma

Partâ… :Relationship of CYP1B1 Genotype-Phenotype and Operative EffectPurposes:To investigate the mutation condition of CYP1B1 gene in Chinese Han infantile glaucoma patients;and to explore the relationship of genotype-phenotype and operative effect.Methods:1.122 unrelated cases of infantile glaucoma patients were recruited in this study. Peripheral blood was collected and genomic DNA was extracted.The coding sequence in exons was amplified by polymerase chain reaction(PCR)from genomic DNA,then direct DNA sequencing was adopted to identify the variants exclusive in the patients.2.Combination with the previous experimental data of our team,we investigated the genotype-phenotype relationship of 238 cases by retrospective study. The analyzed factors included sex,single/both eyes involvement,onset age, intraocular pressure at onset,diameter of cornea,and score of cornea's transparence.3.We reviewed the operative effect of 306 eyes in 192 consecutive patients by multiple factors analysis,which underwent initial surgery in our hospital.Seven factors of onset age,time between onset-operate,style of operate,preoperative intraocular pressure,diameter of cornea,score of cornea's transparence,and mutant status of CYP1B1 gene were subjected to multivariate analysis by logistic regression. Cox proportional hazards regression modeling were used to analyze successful time and trace the survival curve.The SPSS13.0 statistical software was used for data analysis,and P value was less than 0.05 as the statistical significance.Results:1.18 different mutations were detected in the 122 cases' coding exons of CYP1B1 gene.Among them,nine mutations were the first checked out in this study. They were g.3836T＞C(p.11W＞R),g.4022delTC(p.73ORFshift,p.221stop), g.4151G＞T(p.116D＞Y),g.4322G＞A(p.173E＞K),g.4338T＞A(p.178V＞E), g.4493G＞A(p.230E＞K),g.4509T＞C(p.235V＞A),g.8137T＞C(p.434W＞R), g.8167C＞T(p.R444stop).There were 21 cases with the exclusive CYP1B1 gene variants in the 122 patients,and the mutation rate was 17.2%.2.Combined with the previous data,there were 41 cases with mutations of CYP1B1 gene in 238 cases.The mutation rate was 17.2%,too.The median onset age of patients with mutant CYP1B1 gene was 2(0-6)months,and that was 6(2-12) months in whom without mutation.The former was earlier than the latter statistical significantly(P＜0.05).The carriers of mutant CYP1B1 gene were graded higher in corneal transparency(P＜0.05).3.In multivariate logistic regression,the status of CYP1B1 gene showed statistically significance as independent protective factors for final outcome (P＜0.001),and the odds ratio less than 1(OR_cyp1b1=0321).In Cox regression,the significant related factors were corneal transparency(P＜0.01)and the status of CYP1B1 gene(P＜0.01),and the odds ratio were OR_Conea=1.846,OR_Cyp1b1=0.468.Conclusions:The mutant CYP1B1 gene is partly related with the infantile glaucoma. The carriers of mutant CYP1B1 gene may be at earlier onset and with poorer corneal transparency.Mutant CYP1B1 gene is the protective factor for operative effect,and the patients with it have higher success rate and longer successful time.Partâ…¡:Genetic Study on Candidate Loci of Infantile GlaucomaPurposes:To investigate the association relation between the occurrence of infantile glaucoma and the GLC3C locus;and to find out the mutational condition of candidate gene ANGPTL7 in GLC3B locus.Methods:1.152 nuclear families(patients and their parents)without mutant CYP1B1 gene were recruited in this study.By using the Fluorescence Labeled Multiplex-PCR Technique,12 short tandem repeats(STRs)were genotyped covering the GLC3C locus,and transmission disequilibrium test(TDT)was performed.2.In the positive regions,16 haplotype tag SNPs(htSNPs)were choosed to construct haplotypes.By means of MALDI-TOF MS(Matrix-assisted laser desorption/ionization Time-of-flight Mass Spectrometry),126 trios were genotyped, and transmission disequilibrium test was applied again.3.96 cases randomly selected to create DNA pools.Five exons of ANGPTL7 gene were amplified by PCR from the DNA pools,then direct DNA sequencing was adopted.Compare the sequence of the patients and the normal population in database.Results:1.By the single STR's TDT,there were three markers existing transmission disequilibrium in GLC3C.They were D14S279(P=0.021),D14S555(P=0.009601) and D14S74(P=0.003421).The region was 0.006cM long.2.All the single htSNPs in the positive STR regions were no statistical difference in TDT.In the block2(rs2111701-rs4020123-rs4903696-rs11159318-rs 177216),the haplotype TAACG was proved to be transmission disequilibrium (P=0.001).After 10⁴ times of Permutation test,the haplotype was still significantly manifesting transmission disequilibrium(P=0.0135).3.As for candidate gene ANGPTL7 in GLC3B locus,the sequence of five exons between the 6 DNA pools(containing 96 patients)and the normal ones in database was not any heterozygosis to be found.Conclusions:We confirmation the GLC3C locus is associated with the infantile glaucoma in Chinese Hans.A haplotype(including five htSNPs and 22 kilo-basepair long)is related on the occurrence of the disease,and further candidate genes screen should be carried out to dig out the pathogenic or susceptible gene.The candidate gene ANGPTL7 in GLC3B maybe not correlated with the Chinese Han infantile glaucoma patients.